The
cast of Son of Frankenstein includes three legends of horror film: Boris Karloff, Bela Lugosi, and Basil Rathbone. Boris Karloff played the
monster for the third and last time; he had played the role twice before; in the 1931 film
Frankenstein and in the 1935 film Bride of Frankenstein. Bela Lugosi played the mad shepherd Ygor
very effectively, and Rathbone played Baron Wolf von Frankenstein, son of
the monster's creator. It's not necessary to see Frankenstein and
Bride of Frankenstein to enjoy Son of Frankenstein.
Events from the first two films which are essential to understanding what's happening
in this film are explained.

Rathbone's character Baron von Frankenstein was separated from his father as a small child and doesn't remember him. 25 years after the supposed death of the monster, Wolf von Frankenstein returns to the ancestral family castle. He believes his father was a genius and it pains him that the name Frankenstein is synonymous with horror and monsters. When Inspector Krogh
of the District Police visits to warn Dr. Frankenstein that the villagers are afraid of him, Frankenstein suggests that the stories about the monster are gross exaggerations. Krogh explains that his arm was ripped right out of its socket by the monster. From the beginning Krogh is suspicious that Dr. Frankenstein is conducting the same type of experiments that his father did.
Krogh also suspects that the monster was not destroyed years ago; there
have been six mysterious deaths in recent years.

Wolf and Elsa von Frankenstein, having just arrived
at the medieval castle meet Inspector Krogh.

Inspector Krogh warns Baron von Frankenstein of the
danger of the monster.

The laboratory, which is partially destroyed, is built on top of a sulpher pit.
Frankenstein meets Ygor, a criminal who survived his own hanging, and now has a
broken neck. Lugosi is wonderful in this role. Ygor shows the doctor a hidden room off the lab,
in which lies the monster -- alive, but unconcious. Ygor asks Dr. Frankenstein to help revive his friend. As a doctor, Frankenstein is fascinated with the monster, calling it wonderful and superhuman. He says, "I, as a man, should destroy him. But as a scientist, I should do everything in my power to bring him back to
conscious life, so that the world can study his abnormal functions. That would vindicate my father and his name would be enshrined among the immortals."

Frankenstein meets the monster.

Dr. Frankenstein
attempts to revive the monster, but believes he has failed. Later, when
his son Peter describes having seen a giant, Frankenstein is very
worried. He finds the monster in the lab, and feels cold fear when
the monster lays his hand on Frankenstein's shoulder. But the monster
faithfully obeys Ygor.

When Dr. Frankenstein discovers that Ygor has been making the monster
kill people, he becomes frightened and angry. The Baron shoots Ygor and
leaves him lying on the floor of the laboratory. In a moving scene, the
monster finds Ygor's body, tenderly picks it up and carries it to a bed.
The monster grieves over the death of his friend, then, enraged, he goes
berserk, tearing apart the laboratory. Up at the castle Inspector Krogh
confronts Dr. Frankenstein, accusing him of controlling the monster who
has been killing villagers. While they are arguing, the monster takes Dr. Frankenstein's young son,
and both Frankenstein and Inspector Krogh rush to the laboratory to save
the boy. In a climactic conclusion, the monster rips off Krogh's arm, and
Frankenstein swings on a huge chain, knocking the monster into the boiling sulphur
pit.

In the final scene the Baron, having decided to take his family away
from the village, gives the deed to the Frankenstein estate to the
villagers, to do with as they please so that they may again have peace of
mind.

I highly recommend this film. The music is appropriately spooky, and the castle is eerie. The set design is superb. The acting by all the players is terrific, and not
campy. From the family's arrival at the train station during a
thunderstorm until the exciting conclusion, the atmosphere is foreboding
and scary.